Hydrazine is an available energy source which has a high energy content and easily converts from a liquid into a hot gas at about 1600.degree. F. Hydrazine has been used on rockets and high power turbine machines but has not typically been used for systems in the range of 10 to 15 horsepower. Small remote piloted aircraft for high altitudes can be operated on 15 to 50 horsepower for obtaining air samples. The difficulty, however, is to have a low weight, high energy capability in an engine.
In designing a piston operated engine with poppet valves there are several problems involved in conventional cam and spring arrangements. Principally, the problems include excessive cooling and/or heat leak problems with the stem arrangement. Also, the actuating train and cam arrangements are excess weight (if they cannot be eliminated). Slider type poppet valves typically have short lives and are complex as compared to a poppet valve actuated by a piston. Any approach which minimizes weight and complexity and is compatible with high temperatures has merit. While there are systems heretofore proposed for eliminating camshafts, none of these systems have addressed the problem of controlling the movement of the poppet valve in a hot gas atmosphere. For reference, a prior art system is disclosed in U.S. Pat. No. 3,842,812 which describes a four cycle internal combustion engine where the poppet valve arrangement is piston actuated and intended to increase the efficiency of supplying fuel. However, the present invention uses no moving parts other than the poppet valve itself.